X-ray shielding tube mount for high voltage rectifier tube



Oct. 13, 1970 w. 1.. HUGHES EI'AL 3,534,215,

X-RAY SHIELDING TUBE MOUNT FOR HIGH VOLTAGE RECTIFIER TUBE Filed Aug. 13, 1968 United States Patent w US. Cl. 313313 9 Claims ABSTRACT OF THE DISCLOSURE A shielding mount is provided for a high voltage rectifier tube and comprises a tube receiving socket having terminal receiving means formed therein for receiving the terminals of a high voltage electron tube, the socket being formed at least in part of an X-ray shielding material comprised by a composition of ferrite dispersed in an electrically insulating solid plastic binder. The socket comprises an outer cup-shaped solid plastic socket housing having terminal prong receiving apertures formed in its bottom for receiving the terminal prongs of a high voltage rectifier tube used in a combination deflection and high voltage supply circuit for a home television receiver. The socket further comprises an inner X-ray shielding liner disposed in the outer plastic socket housing with the inner X-ray shielding liner being comprised by barium ferrite (BaFe O dispersed in a solid plastic binder. The inner shielding liner is comprised of a minimum of sixty five percent (65%) barium ferrite (BaFe O by volume dispersed in a solid vinyl plastic binder such as polyvinylchloride.

BACKGROUND OF INVENTION Field of invention This invention relates to a new and improved X-ray shielding tube mount for high voltage electron tubes such as high voltage rectifier tubes.

More particularly, the invention relates to an X-ray shielding tube mount for the high voltage rectifier tube of a combination deflection and high voltage supply circuit for a home television receiving set.

Prior art problem It is the usual practice in constructing commercial, home television receiving sets to incorporate a high voltage supply circuit into a combination deflection and high voltage supply circuit thereby economizing on magnetic components. In particular, such a combination high voltage supply and deflection circuit avoids the ne d for a separate, large, heavy and generally expensive magnetic core member for both the deflection assembly and the high voltage supply normally required in connection with the cathode ray tube employed in such television receivers. However, such a combined arrangement requires that the deflection assembly and the high voltage supply be inter-related through the medium of the commonly shared core member and be in close proximity to each other. For this reason, in the design of such combination deflection and high voltage supply circuits, it is essential that the high voltage supply portion of the circuit not adversely affect the operation of the deflection assembly.

With the continued emphasis on safe design of home appliances, considerable effort is being expended to eliminate or to minimize to the greatest extent possible, all hazards present in home television receivers. One of the known hazards of home television receivers is the possibility of X-ray emission from the high voltage rectifier tube used in the high voltage supply circuit for the cathode ray tube employed in the receiver. To minimize such X-ray emission it is desirable to provide shielding around the Patented Oct. 13, 1970 high voltage rectifier tube. However, shielding structures heretofore known have employed lead or other similar metals or metal alloys, and the presence of such known shielding materials in the vicinity of the deflection assembly (necessitated by the very nature of the combination deflection and high voltage supply circuit) adversely affects the magnetics of the deflection assembly. To over come this problem, the present invention was devised.

SUMMARY OF INVENTION It is therefore a primary object of the present invention to provide a new and improved X-ray shielding tube mount for high voltage electron tubes which does not upset the tuning or otherwise adversely affect the magnetic operation of other components or sub-assemblies of an electronic equipment in which the shielding tube mount is used.

Another object of the invention is to provide an X-ray shielding tube mount for the high voltage rectifier tube of a combination deflection and high voltage supply circuit for a home television receiving set, and which does not adversely affect or otherwise upset the magn tics of the deflection assembly portion of such a combination circuit.

In practicing the invention a shielding mount for a high voltage rectifier tube is provided which comprises a tube receiving socket having terminal receiving means formed therein for receiving the terminals of a high voltage electron tube. The socket is formed at least in part of an X-ray shielding material comprised by a composition of ferrite dispersed in an electrically insulating solid plastic binder. The socket employed in the shielding mount preferably comprises an outer cup-shaped solid plastic socket housing having terminal prong receiving apertures formed in the bottom thereof for receiving the terminal prongs of a high voltage rectifier tube used in a combination deflection and high voltage supply circuit for a television receiver. The socket further comprises an inner X-ray shielding liner disposed in the outer plastic socket housing with the inner X-ray shielding liner being comprised by barium ferrite (BaFe O dispersed in a solid plastic binder. The inner shielding liner is comprised of a minimum of sixty-five percent (65 barium ferrite (BaFe O by volume dispersed in a solid vinyl plastic binder such as polyvinylchloride.

BRIEF DESCRIPTION OF DRAWINGS Other objects, features and many of the attendant advantages of this invention will be appreciated more readily as the same becomes better understood by reference to the following detailed description, when considered in connection with the accompanying drawings, wherein like parts in each of the several figures are identified by the same reference character, and wherein:

FIG. 1 is a longitudinal sectional view of a new and improved X-ray shielding tube mount for a high voltage rectifier tube constructed in accordance with the invention;

FIG. 2 is a top plan view of the tube mount shown in FIG. 1;

FIG. 3 is a side view of an open-ended generally cylindrical side portion of the X-ray shielding inner liner comprising a part of the tube mount shown in FIG. 1; and

FIG. 4 is a plan view of an annularly shaped, washerlike bottom portion of the inner, X-ray shielding liner comprising a part of the tube mount shown in FIG. 1, and is used in conjunction with the open ended, cylindrically-shaped side portion shown in FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT FIG. 1 is a longitudinal sectional view of an X-ray shielding tube mount for high voltage rectifier tubes constructed in accordance with the invention. The shielding tube mount shown in FIG. 1 is comprised by a tube receiving socket having terminal receiving means in the form of apertures for receiving the terminals of a high voltage electron tube shown in phantom by the dash-dot lines at 11. As will be appreciated more fully hereinafter the socket is generally cup-shaped and is formed at least in part of an X-ray shielding material comprised by a composition of barium ferrite (BaFe O dispersed in an electrically insulating solid plastic binder. The cupshaped socket is comprrised of an outer cup-shaped, solid plastic socket housing 12 which is of molded, integral construction and may comprise, for example, a solid vinyl plastic such as polyvinylchloride. The outer, cup-shaped solid vinyl plastic socket housing 12 includes a web-like bottom portion 13 having a raised platform area 14 in which a plurality of terminal prong receiving apertures shown at 15 are formed. The apertures 15 preferably have electrically conductive, resilient metal clamps sup ported therein which have ear portions shown at 16 suspended therefrom for connection to the various electrical leads supplying the high voltage rectifier tube 11. The terminal prongs of the high voltage rectifier tube, such as is indicated at 11, are adapted to be received in and provide electrical connection with the metallic clamping members 16 supported in apertures 15. The overall arrangement is also shown in the plan view of FIG. 2 wherein it will be appreciated that there is a central open aperture 17 formed in the bottom portion of outer housing 12 which has a keying slot 18 for use in properly aligning a high voltage rectifier tube in the tube mounting.

The shielding mount illustrated in FIG. 1 is also comprised by a two part inner, X-ray shielding liner shown at 21 and at 22 which is disposed in the outer cup-shaped plastic socket housing 12 and substantially surrounds the high voltage rectifier tube 11. As will best be appreciated from FIG. 2 and FIG. 3 of the drawings, the liner portion 21 comprises an open ended, generally cylindrically shaped side portion having a wall thickness of about .06 inch and which is fabricated from a material that is comprised of a minimum of sixty-five percent (65%) barium ferrite (BaFe by volume dispersed in a solid plastic binder. The solid plastic binder is believed to comprise a solid vinyl plastic binder such as polyvinylchloride. This material is manufactured and sold commercially by the B. F. Goodrich Company and is identified as B. F. Goodrich barium ferrite compound, with the tradename, Koroseal. A similar composition comprised by about sixty-five percent (65%) barium ferrite (BaFe O dispersed in a solid plastic binder is also manufactured and sold commercially by the Minnesota Mining and Manufacturing Company. This material has electrically insulating properties, it is extrudable and moldable to any desired shape, it is flexible at room temperatures, and it is flame retardant. Most importantly, this material does not distort or upset the magnetics or tuning of a magnetically operable electronic component which is disposed adjacent to it. Further, it has been determined that the barium ferrite (BaFe O dispersed in a solid vinyl plastic binder material attenuates X-rays having an energy of about 30 kvp. emitted by the high voltage rectifier tube'll by a ratio of about thirty to one.

In addition to the open ended cylindrically shaped side portion 21, the inner, X-ray shielding liner is further comprised by a separable, flat, annular, washer-shaped bottom portion 22 that has a thickness of about .06 inch and is separable from the cylindrically-shaped side portion 21. Bottom portion 22 is adapted to sit on the bottom or web portion 13 of the cup-shaped outer solid plastic housing 12, and surrounds the terminal prong receiving apertures 15 formed in the raised platform portion 14. The configuration of the annular bottom portion 22 of the inner X-ray shielding liner is best shown in FIG. 4 wherein it can be seen that the outer circumferential edge of bottom portion 22 includes a rather wide notch 23. This wide notch 23 is designed to accommodate a chimney portion 24 of the molded, cup-shaped outer plastic housing 12 which is designed to accommodate the filament leads shown at 25 of a high voltage rectifier tube 11 supported in the tube mount. With this arrangement, and because of its flexibility, the cylindrically shaped side portion 21 may be compressed inwardly in the area of the chimney portion as shown generally at 26. It is, of course, necessary that the molded chimney portion 24 not compress the sides of the inner liner 21 inwardly too much in order that the high voltage rectifier tube 11 can be accommodated in the remaining space.

The two-part construction of the inner liner, and the separable inner liner and outer plastic socket housing makes assembly of the tube mount quite easy, and readily accomplished by unskilled labor. If desired, the inner liner side portion 21 and annular bottom portion 22 may be secured to the outer cup-shaped plastic socket housing by a suitable adhesive during assembly of the tube mount. Upon completion of assembly, it will be seen that the generally cylindrical sidewall portion of the inner X-ray shielding liner 21 and also the sidewalls of the outer cupshaped plastic socket housing substantially surround the high voltage rectifier tube 11 so as to attenuate effectively all X-ray emission from the high voltage rectifier tube during operation. Further, by reason of the characteristics of the ferrite material, the X-ray shielding liner portions 21 and 22 do not adversely affect the magnetic operation of other electronic components and subassemblies of an equipment in which the tube mount is used.

The above characteristics make the new and improved X-ray shielding tube mount particularly desirable for use in combination deflection and high voltage supply circuits for home television receivers where the filament leads 25 normally are quite short and encircle the C-core of the horizontal deflection assembly (for example) of the television receiving set. Under these conditions, of necessity, the high voltage rectifier tube and tube mount are mounted in close proximity to the C-core of the horizontal deflection assembly. However, by reason of the inclusion of the X-ray shielding liner 21 and 22, and because of its unique characteristics, the shielding tube mount will not adversely affect the magnetic operation of the deflection assembly, but at the same time provides adequate X-ray shielding.

From the foregoing description, it will be appreciated that the present invention provides a new and improved X-ray shielding tube mount for high voltage electron devices which does not upset the tuning or otherwise adversely affect the magnetic operation of other components or sub-assemblies of an electronic equipment in which the shielding tube mount is used. The shielding tube mount is particularly suitable for use with the high voltage rectifier tube of a combination deflection and high voltage supply circuit for a home television receiver set, and does not adversely affect or otherwise upset the magnetics of the deflection system portion of such a combination circuit.

Having described one embodiment of a new and improved X-ray shielding tube mount for high voltage rectifier tubes constructed in accordance with the invention, it is believed obvious that other modifications and variations of the invention are possible in the light of the above teachings. It is, therefore, to be understood that changes may be made in the particular embodiment of the invention described which are within the full intended scope of the invention as defined by the appended claims.

What is claimed is:

1. A shielding mount for a high voltage rectifier tube comprising a tube receiving socket having terminal receiving means formed therein for receiving the terminals of a high voltage electron tube, the socket being formed at least in part of an X-ray shielding material comprised by a composition of ferrite dispersed in an electrically insulating solid plastic binder.

2. A shielding mount according to claim 1 wherein the X-ray shielding material is comprised by barium ferrite (BaFe O dispersed in a solid plastic binder.

3. A shielding mount according to claim 2 wherein the X-ray shielding material comprises a minimum of sixtyfive percent (65%) barium ferrite (BaFe O by volume dispersed in a solid plastic binder.

4. A shielding mount according to claim 3 wherein the X-ray shielding material is comprised in part of a solid vinyl plastic such as polyvinyl chloride.

5. A shielding mount according to claim 1 wherein the socket comprises an outer cup-shaped solid plastic socket housing having terminal prong receiving apertures formed in the bottom thereof for receiving the terminal prongs of a high voltage rectifier tube used in a combination deflection and high voltage supply circuit for a television receiver, and an inner X-ray shielding liner disposed in said outer plastic socket housing, said inner X-ray shielding liner being comprised by barium ferrite (BaFe O dispersed in a solid plastic binder.

6. A shielding mount according to claim 5 wherein the sides of the cup-shaped outer solid plastic housing and inner shielding liner are cylindrically-shaped and substantially surround a high voltage rectifier tube sup ported within the shielding mount.

7. A shielding mount according to claim 6 wherein the inner shielding liner is separable from the Outer solid plastic housing and is comprised of an open ended cylindrically-shaped side portion and flat annular washer shape bottom portion that is separable from th cylindricallyshaped side portion and sits on the bottom of the cupshaped outer solid plastic housing so as to surround the terminal prong receiving apertures formed in the bottom of the outer housing.

8. A shielding mount according to claim 7 wherein the inner shielding liner is comprised of a minimum of sixtyfive per cent barium ferrite (BaFe O by volume dispersed in a solid plastic binder.

9. A shielding mount according to claim 8 wherein the inner shielding liner is comprised in part of a solid vinyl plastic binder such as polyvinylchloride.

References Cited UNITED STATES PATENTS 3,148,280 9/1964 Kleber et al. 250-108 JOHN W. HUCKERT, Primary Examiner R. F. POLISSACK, Assistant Examiner U.S. Cl. X.R. 

